In many sports, such as football, baseball, basketball, hockey, tennis, and others, a sport object such as a ball or a puck is moved in a specified manner in order to score points and win the contest. The object may be passed or moved between different players of the sport with the objective of scoring points by forcing the object past, through, or into a goal. For instance in football, the football can be handed off or passed between players on the same team to move the football toward the goal line. Among other means, points are scored by a football team if a member of that team crosses the goal line with the football or catches a pass in the end zone. A baseball hit over a wall at the edge of the playing field scores a point, i.e., a run, while a baseball hit within the playing field but sufficiently far away from members of the defending team also has the possibility of scoring. The objective in tennis, on the other hand, is to keep the ball within a specified playing area but hopefully where it is difficult or impossible for the player's opponent to return it to the playing area on the opposite side of the net.
The relatively small size of the sport object and its often rapid movement during play can make it difficult for television viewers to find and follow the object while watching the sport during real-time motion and sometimes even during slow motion replays. Various techniques have been used to detect the position of the sport object and to track its movement. In particular, hockey pucks have been fabricated with infrared emitting diodes mounted flush on their surfaces with the emitted infrared radiation being detected by special cameras. Proposals have also employed optical recognition or pattern recognition techniques.